• Level: 10
• Casting Time: 1 action or bonus action
• Range: Sight
• Components: V, S (the caster's own blood, drawn as part of the casting)
• Duration: Instantaneous
• School: Necromancy
• Classes: Sorcerer, Wizard

Spell Description: Originally wielded by a formidable entity that mastered both blood and fire, Bloodseeker's Revelation channels the user's life essence into a potent force of destruction and enlightenment. This ancient spell, requiring no magical expenditure, utilizes the caster's blood to form a connection, delivering a devastating attack while revealing deep insights into the target's being.

Mechanics:

1. Health Cost: The caster suffers 50 HP damage, a sacrificial act that fuels the spell's potency without depleting their magical reserves.
2. Damage Output: Inflicts 30d8 piercing (or slashing or bludgeoning) plus 30d8 fire damage, mirroring the dual nature of the original entity's power. The choice of physical damage type can be made at casting to exploit specific vulnerabilities.
3. Knowledge Gain: Success grants the caster immediate and comprehensive knowledge of the target’s current HP, AC, movement speeds, senses, resistances, immunities, ability scores, and saving throw modifiers.
4. Non-Spell Nature: True to its origins, this attack does not count as a spell, bypassing conventional limits on spellcasting in a turn and allowing for simultaneous magical actions.

Note: Bloodseeker's Revelation is a legacy of a bygone epoch, a testament to the raw power that once flowed through the veins of its ancient wielder. It serves as a dire weapon and a beacon of knowledge, offering those who dare to invoke it a glimpse into the pinnacle of arcane and sanguine mastery.